KR20160080298A - Mortar composition using beta-hemihydrate gypsum and mortar for floor finishing using thereof - Google Patents

Abstract

The present invention relates to a mortar composition using β-hemihydrate gypsum, and mortar using the same. More particularly, the mortar composition comprises: β-hemihydrate gypsum which is an industry byproduct; a slag fine powder which can complement final strength; components for reducing dry shrinkage and preventing cracks, which include anhydrite and cement; accelerating agent; calcium carbonate; and an admixture such as an retarding agent, an antifoamer, or the like. The mortar composition is environment-friendly, and has a short curing period, thereby having excellent cost-efficiency, and complemented strength and self-leveling performance.

Description

[0001] Mortar compositions using beta-hemihydrate gypsum and mortars for floor finishing [0002]

The present invention relates to a mortar composition using β-hemihydrate gypsum and to a mortar using the same. More particularly, the present invention relates to β-hemihydrate gypsum which is an industrial by-product and slag fine powder which can complement late strength, The present invention relates to a mortar composition and a mortar using the mortar composition, which is environmentally friendly, has excellent economical efficiency due to shortened curing period, and has improved strength and self-leveling performance by containing an admixture such as gypsum, cement, a water-dispersible material, calcium carbonate and retarder and defoamer.

Cement mortars based on cement, fine aggregate, and admixture are widely used as bottom mortar for use in apartment buildings or general houses due to economical efficiency and convenience. However, the cement mortar has a problem that the construction period is long due to a long curing time, cracks due to drying shrinkage, deterioration of initial strength development, and the like. Therefore, in order to overcome such disadvantages, researches are being conducted to use desulfurization gypsum, which is a byproduct generated in a thermal power plant.

In general, the gypsum powder is self-smoothing, has some swelling during curing and is excellent in dimensional stability, and is the most useful material for horizontal self-leveling mortar. It is composed of CaSO ₄ · 2H ₂ O, CaSO ₄ · 1 / 2H ₂ O), Type III, and Type II anhydrous gypsum. Among them, the α-hemihydrate (calcium sulfate alpha-hemihydrate) is produced by using an autoclave reactor at a temperature of 100 to 150 ° C. Therefore, the production cost is high, And so on. On the other hand, β-hemihydrate (calcium sulfate beta-hemihydrate, β-hemihydrate, hereinafter referred to as β-hemihydrate) is inexpensive to manufacture but is used mainly as a gypsum board and cement modifier .

A mortar composition using an α-hemihydrate gypsum prepared by treating a desulfurized gypsum by a hydrothermal method has been disclosed (for example, Korean Patent No. 10-2009-0114192 and No. 10-2005-01255541) Since it is necessary to mass-produce cement mortar in order to be widely applied, the construction rate of mortar mainly composed of α-hemihydrate gypsum, which is limited in mass production, is low.

However, the production of desulfurization gypsum is expected to increase sharply due to the increase in thermal power plants for power supply and expansion of flue gas desulfurization facilities. Therefore, the development of a mortar composition which can improve economical efficiency by shortening the curing time, which is an industrial by-product which is low in firing cost and capable of mass production, as a main component, and which is eco-friendly and can secure strength and self-leveling performance .

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a slag fine powder which can be used as a by- The present invention provides a mortar composition and a mortar using the mortar composition, which is environmentally friendly, has a short curing period, is excellent in economic efficiency, and has improved strength and self-leveling performance by containing an admixture such as calcium carbonate, retarder and antifoaming agent.

In order to solve the above-mentioned technical problems, the present invention provides a process for producing a composition comprising 50 to 60 parts by weight of β-hemihydrate based on 100 parts by weight of the total composition; 1 to 6 parts by weight of anhydrous gypsum; 1 to 6 parts by weight of cement; 1 to 25 parts by weight of a slag fine powder; 1 to 5 parts by weight of a filler; 1 to 20 parts by weight of calcium carbonate; And 0.01 to 5 parts by weight of an admixture selected from retardants, defoamers, thickeners, fluidizers, resins and combinations thereof.

According to another aspect of the present invention, there is provided a mortar formed using the mortar composition.

The mortar composition according to the present invention can be used as an industrial by-product, such as β-hemihydrate gypsum and slag fine powder which can complement late strength, anhydrite gypsum, cement, a filler, calcium carbonate and retarder, defoamer Since it contains an admixture, it is possible to provide a mortar which is eco-friendly, has a short curing period, is excellent in economy, and has strength and self-leveling performance complemented.

Hereinafter, the present invention will be described in more detail.

The mortar composition of the present invention comprises, based on 100 parts by weight of the total composition, 50 to 60 parts by weight of? 1 to 6 parts by weight of anhydrous gypsum; 1 to 6 parts by weight of cement; 1 to 25 parts by weight of a slag fine powder; 1 to 5 parts by weight of a filler; 1 to 20 parts by weight of calcium carbonate; And 0.01 to 5 parts by weight of an admixture selected from retardants, defoaming agents, thickening agents, fluidizing agents, resins and combinations thereof.

The mortar composition of the present invention does not use α-hemihydrate gypsum at all, and since the amount of β-hemihydrate gypsum incorporated is 50 to 60 parts by weight (more preferably 52 to 60 parts by weight) relative to 100 parts by weight of the total composition, Can be maximized. When the amount of β-hemihydrate gypsum is less than 50 parts by weight, there is a problem that the manufacturing cost is increased by utilizing less by-products of the industry. When the amount of β-hemihydrate is more than 60 parts by weight, the amount of mixed water increases and the required compressive strength can not be obtained.

When water is added after mixing the β-hemihydrate, the anhydrous gypsum, the cement, the slag fine powder, the filler, the calcium carbonate and the admixture, the hydration reaction causes ettringite (Calcium Sulfor Aluminate, 3CaO · Al ₂ O ₃ 3CaSO ₄ .32H ₂ O)), and the strength of the slag powder is increased over a long period of time owing to the latent hydraulic properties of the fine powder of the slag, so that the disadvantage that the long-term strength of the β- have.

Although not particularly limited, the? -Hexaete gypsum may have an average particle diameter of 10 to 50 μm and contain 1 to 6% by weight of crystals. For example, a desulfurized gypsum having an average particle size of 30 to 60 μm, a free water content of 10% and a purity of 90% or more is obtained from a thermal power plant and dried at 80 to 90 ° C. in a case mill. And then subjected to a sintering and grinding step at an impact mill of 150 to 160 ° C in a second order to obtain a β-hemihydrate gypsum having an average particle size of 10 to 50 μm, which can be used in the present invention.

The mortar composition of the present invention comprises 1 to 6 parts by weight (more preferably 1 to 5 parts by weight) of anhydrous gypsum based on 100 parts by weight of the total composition. If the amount of the anhydrous gypsum used is less than 1 part by weight, the coagulation time is shortened and there is a problem in securing workability. If the amount is more than 6 parts by weight, the coagulation time is delayed and the manufacturing cost is increased.

The anhydrous gypsum preferably has a specific surface area of about 3,000 to 6,000 cm < 2 > / g.

The mortar composition of the present invention comprises 1 to 6 parts by weight (more preferably 2 to 5 parts by weight) of cement based on 100 parts by weight of the total composition. If the amount of the cement is less than 1 part by weight, the compressive strength developed in the mortar is low and the required strength can not be obtained. If the amount of the cement is more than 6 parts by weight, the utilization of industrial byproducts is reduced.

The cement may be at least one selected from Fe ₂ O ₃ , SO ₃ and MgO. In this case, for example, Fe ₂ O ₃ may be contained in an amount of 0.5 wt% or less, SO ₃ to 3.5 wt% or less, and MgO to 5.0 wt% or less, but not limited thereto.

The mortar composition of the present invention comprises 1 to 25 parts by weight (more preferably 16 to 21 parts by weight) of a slug fine powder based on 100 parts by weight of the total composition. When the amount of the slag fine powder used is less than 1 part by weight, there is a problem that the long-term strength of the mortar is lowered, and when it exceeds 25 parts by weight, the initial strength of the mortar is lowered.

Although not specifically limited, the slag powder includes 4.0 to 8.0 wt% of MgO and 2.0 to 3.0 wt% of SO ₃ , and has a density of 2.80 to 2.95 g / cm 3, an average particle diameter of 8 to 12 탆, and a specific surface area of 4,000 to 6,000 cm 2 / g Can be used.

The mortar composition of the present invention comprises 1 to 5 parts by weight (more preferably 1 to 3 parts by weight) of a filler based on 100 parts by weight of the total composition. If the amount of the water-dispersible material is less than 1 part by weight, high-strength mortar can be produced, but desired strength can not be obtained. If it exceeds 5 parts by weight, the compression strength is good.

Preferably, calcium sulfate sulfoaluminate (CSA), Na ₂ SO ₄ and a combination thereof may be used as the above-mentioned filler. The calcium sulfoaluminate may be, for example, 50.0 to 53.6% by weight of CaO, ₃ 27.0 to 31.0% by weight and Al ₂ O ₃ 12.0 to 15.0% by weight, a specific gravity of 2.8 to 3.0, a specific surface area of 2,000 to 3,000 cm 2 / g and a chloride content of 0.05 or less can be used. .

The mortar composition of the present invention comprises 1 to 20 parts by weight (more preferably 13 to 16 parts by weight) of calcium carbonate used as a filler based on 100 parts by weight of the total composition. If the amount of calcium carbonate used is less than 1 part by weight, the effect required by the filler can not be obtained. If the amount is more than 20 parts by weight, the manufacturing cost increases and the economical efficiency is lowered.

Although not particularly limited, calcium carbonate may be used having a density of 2.65 to 2.72 g / cm3, an average particle diameter of 9 to 11 占 퐉, a water content of 0.2% by weight or less and a thickness of 2 占 퐉 or less (%)?

The mortar composition of the present invention comprises 0.01 to 5 parts by weight (more preferably 0.04 to 0.3 part by weight) of an admixture selected from retardants, defoaming agents, thickening agents, fluidizers, resins and combinations thereof based on 100 parts by weight of the total composition .

The mortar composition of the present invention comprises 0.01 to 1 part by weight of a retarder based on 100 parts by weight of the total composition in order to delay workability of the β-hemihydrate gypsum and to secure working time. As the retarder, a polyamide compound, citric acid, tartaric acid, or a combination thereof may be used. As the polyamide compound, for example, calcium-added polyamide compound may be used, but the present invention is not limited thereto.

The mortar composition of the present invention contains 0.01 to 1 part by weight of an antifoaming agent based on 100 parts by weight of the total composition in order to obtain a clean finished surface by removing air bubbles in the mortar and to secure the strength enhancement. As the defoaming agent, those selected from ester, fatty acid, mineral oil, alcohol, amide, silicone and combinations thereof may be used. For example, a defoaming agent in powder form having a pH of 7.5 and a density of 0.55 g / But is not limited thereto.

The mortar composition of the present invention contains 0.01 to 1 part by weight of a thickener based on 100 parts by weight of the total composition in order to improve adhesion and workability and to prevent segregation of materials and improve workability. As the thickening agent, methyl cellulose, hydroxymethyl cellulose, carboxymethyl cellulose, ethyl cellulose, hydroxyethyl cellulose, and combinations thereof may be used, but the present invention is not limited thereto.

The mortar composition of the present invention comprises 0.01 to 1 part by weight of a fluidizing agent based on 100 parts by weight of the total composition for improving the workability and strength, improving fluidity, shortening the curing time, reducing the water sensitivity, etc. Examples of the fluidizing agent include, but are not limited to, melamine-based, polycarbonate-based, naphthalene-based, lignin-based, and combinations thereof.

The mortar composition of the present invention comprises from 0.01 to 1 part by weight of a resin based on 100 parts by weight of the total composition to improve adhesion and flexural strength and increase abrasion resistance. As the resin, a resin selected from a vinyl acetate-ethylene copolymer, an acrylic resin, a glass fiber, a silica-based resin, a vinyl acetate resin, and a combination thereof may be used, but is not limited thereto.

The mortar composition blended with the above components has an advantage that it has a little swelling property and therefore has less cracking occurrence than cement mortar and has high fluidity based on the smoothness of the gypsum itself. The mortar composition of the present invention preferably has a setting time (preferably 1 hour to 4 hours, more preferably 1 to 3 hours) and a termination time of 15 hours or less (for example, 4 to 15 hours , More preferably 4 to 8 hours). In addition, since the self-leveling performance is excellent due to the β-hemihydrate gypsum having smoothness, a separate finishing process is not required since the self-leveling performance is self-leveling by swelling on the floor surface of the building. There is no occurrence.

According to another aspect of the present invention, there is provided a mortar formed using the mortar composition.

The mortar of the present invention can be produced, for example, by mixing 35 to 60 parts by weight of water with respect to 100 parts by weight of the mortar composition, and more specifically, by mixing 40 to 55 parts by weight of water, but is not limited thereto. The mortar of the present invention is an improvement of the problem of strength deterioration of existing β-semi-rigid high-grade mortar and can exhibit a compressive strength of 200 kgf / cm 2 or more (for example, 200 to 500 kgf / . The mortar of the present invention can be used in a variety of applications as a building material and can be used, for example, for floor finish applications (i.e., floor finish applications).

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, the scope of the present invention is not limited thereto.

[ Example ]

Table 1 shows the flowability, compressive strength and coagulation time of the mortar prepared using the mortar composition blended with the composition shown in Table 1.

The mortar was prepared according to the mechanical mixing method of KS L 5109 hydraulic cement paste and mortar, and the flowability of the mortar composition was measured according to the method specified in KS L 5109, and the compressive strength test method of KS L 5105 hydraulic cement mortar The compressive strength of the mortar was measured at 3, 7, and 28 days of age. The measured physical properties are shown in Table 2.

[Ingredients of raw materials]

β-hemihydrate Gypsum: average particle diameter 25 μm, content of crystals 5 wt%

Anhydrous gypsum: natural anhydrous gypsum (Qinghai), specific surface area of about 4,000㎠ / g

Cement: White ordinary Portland cement (Union)

Slag fine powder: density 2.90 g / cm 3, average particle size 10 탆, residual 45 탆 1.0%, water 0.2%, specific surface area 5,000 cm 2 / g

Calcium carbonate: density 2.68 g / cm3, average particle diameter 10 占 퐉, water 0.2 weight% or less, less than 2 占 퐉 (%)? 15

Retardant: calcium-added polyamide compound [PLAST RETARD PE, (SICIT 2000 S.p.A)]

Defoamer: - Agitan P841

Thickener: Bermocoll M10, M30 (low viscosity, high viscosity thickener)

Fluidizer: Conpac 149S

Resin: VINNAPAS 5111L

Example  One

The components of the composition shown in Table 1 were mixed to prepare a mortar composition, and 45 parts by weight of water was mixed with 100 parts by weight of the mortar composition to prepare a mortar.

Example  2

The components of the composition shown in Table 1 were mixed to prepare a mortar composition, and 45 parts by weight of water was mixed with 100 parts by weight of the mortar composition to prepare a mortar.

Example  3

The components of the composition shown in Table 1 were mixed to prepare a mortar composition, and 50 parts by weight of water was mixed with 100 parts by weight of the mortar composition to prepare a mortar.

Comparative Example  One

The components of the composition shown in Table 1 were mixed to prepare a mortar composition, and 45 parts by weight of water was mixed with 100 parts by weight of the mortar composition to prepare a mortar.

Comparative Example  2

The components of the composition shown in Table 1 were mixed to prepare a mortar composition, and 50 parts by weight of water was mixed with 100 parts by weight of the mortar composition to prepare a mortar.

Comparative Example  3

The components of the composition shown in Table 1 were mixed to prepare a mortar composition, and 50 parts by weight of water was mixed with 100 parts by weight of the mortar composition to prepare a mortar.

The setting time and the compressive strength of the gypsum mortar obtained in Examples 1 to 3 were found to be appropriate values for the criteria of the mortar for bottoming [compression strength: 200 kgf / cm 2 or more, setting time: . However, when the β-hemihydrate gypsum is excessively contained as in Comparative Example 1, the coagulation time progresses rapidly, and it is impossible to secure a suitable working time, and it is confirmed that the compressive strength is below the standard value. Further, in the case of Comparative Example 2, it was confirmed that the mortar composition did not include a filler, contained a small amount of slag fine powder, and contained the silica sand fine aggregate, so that the compressive strength was low and the setting time was slow. The compressive strength is similar to that of the example, but the production cost is relatively low due to the small amount of β-hemihydrate.

As described above, the mortar composition of the present invention was able to produce gypsum mortar having suitable workability, compressive strength and self-leveling property.

Claims (17)

50 to 60 parts by weight of? -Hexaete gypsum, based on 100 parts by weight of the total composition; 1 to 6 parts by weight of anhydrous gypsum; 1 to 6 parts by weight of cement; 1 to 25 parts by weight of a slag fine powder; 1 to 5 parts by weight of a filler; 1 to 20 parts by weight of calcium carbonate; And 0.01 to 5 parts by weight of an admixture selected from retardants, defoamers, thickeners, fluidizers, resins and combinations thereof. The mortar composition according to claim 1, wherein the β-hemihydrate has an average particle size of 10 to 50 μm and a crystalline water content of 1 to 6% by weight. The mortar composition according to claim 1, wherein the β-hemihydrate gypsum is obtained by drying the desulfurized gypsum in a case mill at 80 to 90 ° C. and calcining and grinding it at 150 to 160 ° C. in an impact mill. The mortar composition according to claim 1, wherein the anhydrous gypsum has a specific surface area of 3,000 to 6,000 cm 2 / g. The mortar composition according to claim 1, wherein the cement is white Portland cement. The slag fine powder according to claim 1, wherein the slag fine powder contains 4.0 to 8.0 wt% of MgO and 2.0 to 3.0 wt% of SO ₃ , the density is 2.80 to 2.95 g / cm 3, the average particle diameter is 8 to 12 탆, 4,000 to 6,000 cm < 2 > / g. The calcium carbonate according to claim 1, wherein the calcium carbonate has a density of 2.65 to 2.72 g / cm3, an average particle diameter of 9 to 11 占 퐉, a water content of 0.2% by weight or less and a thickness of 2 占 퐉 or less , Mortar composition. The method according to claim 1, wherein the filler is selected from the group consisting of calcium sulfoaluminate (CSA), Na ₂ SO ₄ ≪ / RTI > and combinations thereof. The mortar composition according to claim 1, wherein the retarder is selected from a polyamide compound, citric acid, tartaric acid, and combinations thereof. The mortar composition according to claim 1, wherein the antifoaming agent is selected from ester, fatty acid, mineral oil, alcohol, amide, silicone and combinations thereof. The mortar composition according to claim 1, wherein the thickener is selected from methylcellulose, hydroxymethylcellulose, carboxymethylcellulose, ethylcellulose, hydroxyethylcellulose, and combinations thereof. The mortar composition according to claim 1, wherein the fluidizing agent is selected from melamine-based, polycarbonate-based, naphthalene-based, lignin-based, and combinations thereof. The mortar composition according to claim 1, wherein the resin is selected from vinyl acetate-ethylene copolymers, acrylic resins, glass fibers, silica-based resins, vinyl acetate resins and combinations thereof. The mortar composition according to claim 1, which exhibits a setting time of not less than 1 hour and a termination time of not more than 15 hours as a setting time. A mortar formed using the mortar composition of any one of claims 1 to 14. The mortar according to claim 15, which is prepared by mixing 35 to 55 parts by weight of water with respect to 100 parts by weight of the mortar composition. 16. The mortar of claim 15, wherein the mortar is a floor finish.